Flexible curve device for drawing-office and other purposes.



H. BROTHERTON.

FLEXIBLE CURVE DEVICE FOR DRAWlNG OFFI CE AND OTHER PURPOSE} APPLICATIONFILED FEB. 3 1915.

'1 9 1 6 1 15 1 Patented Nov. 23, 1915.

HARRISON BRQTHERTON, OF ASHTON-UPON-MERSEY, ENG-LAND.

FLEXIBLE CURVE DEVICE FOR DRAWING-OFFICE AND OTHER PURPOSES.

Application filed February 3, 1915. Serial No. 5,940.

T all whom it may concern:

Be it known that I, Hainnso'x Bnorrmn- TON, subject of the King of GreatBritain and Ireland, and resident of Ashton-uporr Mersey, in the countyof Chester, England, have invented certain new and useful Improvementsin Flexible Curve Devices for Drawing-Office and other Purposes, ofwhich the following is a specification.

My invention relates to improvements in flexible curve devices such asmaybe employed for-the same or similar purposes as French curves indrawing ofiices and for use in plotting out or filling in curves inefiicicncy and other diagrams or for other purposes where a devicecapable of almost infinite variation of curvature would be I founduseful.

My invention consists in its simplest form of a pair of compass legsconnected together at one end by a pivot pin common to them both andhaving at the other endsrof the legs slotted clamping studs directlymounted in holes therein and capable of being adjusted about the centersof said holes, said studs carrying the flexible strip the curvature ofwhich. is to be varied. lln a modified form of the device I connect thecompass legs or arms by clamping studs to the ends of a central linkwhich enables still further variations of curvature of the strip to beobtained. I may combine with the aforesaid feature means for supportingthe flexible strip at points intermediate of the main supporting studs.

My invention will be fully described with reference to the accompanyingdrawings in which Figure 1 is a plan of the improved device forming thesubject matter of my invention,

Fig. 2 separated plans of connecting links hereinafter referred to, Fig.3 plan of the de vice shown. in Fig. 1, Fig. 4 longitudinal section ofone of the rotatable studs and, Fig.5

' longitudinal section of one of the intermestrip may be drawn through.its stud to Specification of Letters Patent.

nected together 'llatented Nov. 23, rain.

vary the character of the curve between the two points at which it isheld.

The arrangement of stud which I at pres ent prefer to employ is one inwhich the slit 7) is made for the greater part. of the length of thestud as shown in Fig. 4, the upper end being reduced in diameter at (Iso as to leave a conical shoulder c to fit in the countersunk portion fof the hole in the outer end of each end link It the shank portionpassing through hole f/ to receive a lever handle 11 by which the studmay be rotated to alter the position of the strip a. The shank islD-shaped to correspond with a similar-shaped hole in the handle 1'- andto clamp the latter, link It and stud together. I employ a shoulderedclamping screw 7', and spring washer m, the

. screw being turned by the pin a, by a milled head or by any othersuitable means. Theeffect of tightening the screw y' is to pull theconical part of stud 11 into the countersunk part f of hole 1 and thusfirmly grip the strip a in the slit 7) and prevent it sliding thereinduring the rotation of the stud to bend the strip a to thecurverequired. A further effect is to tighten the joint parts to givesufficient friction to enable the stud and parts tobe held in theadjusted position steadily, though the screw y may be tightened upsufiiciently if required to prevent any movement of the. parts afteradjustment. When the parts are quite slack the strip a can be movedfreely through the slit 6. Each stud 0 may be rotated separately ineither direction.v i

The links or arms h may be directly conordinary compass joint or by aclamping stud such as 0, Fig. 5 which is very similar to those at theends except it is Witliat their innereends by anout a slit. The arms itmay be extendedv or I be closed in about their pivoted center and thusagain enable the character of the curve formed by the'strip to bevaried. The curve may have its convex side nearest to the joint of thehinged arms or the concave side may be nearest thereto. Instead ofcoupling the inner ends of the arms 7a directly at their central point Imay couple them to a link 7), as shown in the drawing such link havingcountersunk holes (1 While the inner ends of links it have square holesto engage with corresponding portions on the shanks of studs 0. Thejoints may be' controlled by screwed studs j as in the end studs. Theemployment of the common n'id linh enables a still greater variation ofeurvatinhe to he given to the strip.

By the means hereinhetore described the strip a. may he made to assumean almost infinite variety of curves, an example heing shown by thethiek black line in Fig. 1 and another example by the broken line in thesame figure.

In cases where there is a considerable length ot'strip a between thestuds its eentral portion may he rigidly supported h v one ormo e arms1* -arried by the hinged arms previously referred to. The outer end ofthe arm may he fitted with a si'nall (lamping stud a secured hy clampingscrew a. A slitted head 5 is adapted to pass over the tlexihle strip.The head't is freely movahle ahout its shank I in the stud a so that it-\\'Ill aeeommmlate itselt' to the eurvature ot oi the jointed arms, allexihle hand slidahle pivoted together and provided with looking adeviees at their pivota slotted studs journaled at the end portions ofthe series of arms. a tiexihle. hand slidahle longitudinally in theslotted studs, and means For locking the hand to the studs and forlocking the studs to the arms.

3. In a drat'tsmans curve, jointed extension arms provided with lookingdevices, slotted studs journaled at the end portions of the jointedarms. a ilexihle hand slidahle longitudinall in the slottedmtuds, a rodhavin] one end pivoted to one of the arms and its other end adjustahlvronneeted to the said hand. and means tor locking the hand to the studsand for locking the studs to the a ms.

in testimony whereof l have hereunto set my hand in the presenee of twowitnesses.

